Steam-generator.



No- 809,366. PATENTED JAN. 9, 1906. D FITZGIBBONS STEAM GENERATOR.APPLICATION FILED MAY 27 1905 WITNESSES.-

UNITED STATES PATENT OFFICE.

STEAM-GENERATOR.

Specification of Letters Patent.

Patented Jan. 9, 1906.

Application filed M y 27, 1905. Serial No. 262,588.

To all whom it may concern:

Be it known that I, DAVID FrrZGIBBoNs, a citizen of the United States,residing at Oswego, in the county of Oswego and State of New York, haveinvented certain new and useful Improvements in Steam-Generators; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to an improved construction of steam-generatorwhich is strong, simple, and economical to manufacture and of a highefficiency.

It consists, essentially, of a vertically-arranged cylindrical shellcontaining the ashpit, grate, fire-box, and combustion-chamber and of ahorizontal cylindrical shell eX- tendingfrom the middle of the verticalshell and containing the tubes. In the vertical v shell is arrangedaninner shell or crownsheet forming a circular fire-box, permitting alarge grate to be used, and a substantially semicircularcombustion-chamber above the fire-box. I have discovered that byconstructing this inner shell or crown-sheet with large easy curvesinstead of with sharp bends I have produced a generator givingsubstantially perfect combustion and a high degree ofefliciency, becausethe gases are unimpeded by sharp turns or corners in their flow to thecombustion-chamber, there is an unimpeded circulation of water aroundthe exterior of the crown-sheet, avoiding the danger of burning, allparts are heated uniformly to a high degree, and more or lessdeadcorners are avoided. Such a crown-sheet is almost or practicallyself-sustaining, requiring few braces, and thus greatly simplifying theconstruction and diminishing the cost of construction and repairs andrendering the boiler easier to becleaned. The furnace and the boiler arecombined. in a generator which is self-containing, self-sustaining, andself-supported. As it needs no foundation, it can be easily used in manylocations.

My invention will be understood by reference to the drawings herewith,in which the reference letters and numerals of the specificationindicate the corresponding parts in both the figures.

Figure I is a side elevation, partly in section, of my completegenerator. Fig. II is a top plan of the crown-sheet detached.

In the figures, 1 indicates the vertical cylindrical shell fitted to anannular casting 2, forming a standard on which the generator issupported.

3 is the damper; 4, the ash-door to the ashit. p 7 is the large gratearranged in the circular fire-box 8, substantially surrounded bywater-leg 10.

11 is a blow-off.

12 is the feed-door.

15 is the inner shell or crown-sheet forming the Water-leg around thefire-box and inclosing in its upper portion the substantiallysemicircular combustion-chamber 16. This crown-sheet is secured by theusual rivets to the outer shell at its lower margin. Where bent at a, b,and c to inclose the fire-box and the-combustion-chamber and to form thehalf-domes 21 and 22, respectively, over the rear of the fire-box andover the combustionchamber the sheet is not bent at right angles,forming sharp corners, but in large curves, the arcs of comparativelylarge circles. It is therefore substantially self-supporting, requiringfor each of said half-domes one brace only, 24 and 25, instead ofseveral. It will be undertood that these curves are made as large aspossible, and, particularly referring to curve I), this is as near aself-sustaining curve as is possible. To carry this curve up any higherin the crown-sheet would cut off some of the tubes. It will beunderstood that each brace added to a boiler involves not only so muchweight and material, but also considerable labor in construction. Wherethe braces are reduced in number, as here shown, and almost done awaywith entirely, the interior of the boiler is not filled up withfunctionally-useless parts, which also positively interfere with theconvenience of access to the interior in case of cleaning and repairs.It will be understood that not only constructionally is this foundationof crownsheet of great importance, but functionally as well, because thelarge curves a and I) do not impede or check the gases like sharp bendsand corners, but permit the gases generated, particularly at the rear ofthe grate, to pass therefrom freely and unimpeded into thecombustion-chamber, eflecting a more uniform and steady combustion, andtherefore a greater efiiciency. By making the curve at a, large there isavoided a more or less dead corner, which in case of a sharp bend is notperfectly reached by the heat, and therefore incompletely heated. Withinthe boiler-space the water circulates more freely, steadily, andunimpeded around these large curves of the crown-sheet than around sharpcorners, thereby avoiding the danger of burning out the metal.

29 represents the stay-bolts securing the crown-sheet in position to thefront of the boiler.

30 is the dome; 31, the steam-pipe; 32, the horizontal cylindricalextension extending rearwardly from about the center of the verticalshell and containing the tubes 33, tapped into the crown-sheet andopening in the combustion-chamber.

34 is the smoke-flue, and 35 a supportingcolumn for the horizontalshell.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a steam-generator, the combination with a vertical cylindricalshell inclosing an ash-pit below, of an inner shell having a cylindricallower portion forming a fire-box and a semicylindrical upper portionforming a combustion-chamber, said inner shell being arranged within thecylindrical shell and having its lower margin connected thereto to forma water-leg around the fire-box, a grate above the ash-pit, a horizontalcylindrical shell extending rearwardly from the vertical shell, tubes inthe horizontal shell secured to the rear wall of the combustion-chamber,and two braces supporting the inner shell in the outer shell, one bracebeing connected to the front higher portion of the inner shell and onebrace bein connected to the rear lower portion of the lnner shell.

2. In a steam-generator, an outer, vertical cylindrical shell, anannular flanged, supporting-casting fitted to the foot of said shell, aninner shell or crown-sheet arranged within the outer shell and rivetedto said outer shell around its lower margin, said inner shell beingformed with a cylindrical lower portion, a semicylindrical upper portionarranged above the front of the lower portion and a straight verticalwall forming the rear face of said upper ortion, said lower portionforming the fire- OX and having a'rear half-dome over the fire-box, saidupper portion forming a combustionchamber and having a front half-domeover the combustion-chamber, the curves between the fire-box wall, andthe rear half-dome, between said rear half-dome and said vertical wall,and between the combustion-chamber front wall and the front half-domebeing curves in the arcs of large circles, and a horizontal, cylindricalshell cfinltlaining tubes extending from the vertical s e 3. In asteam-generator, an outer cylindrical shell, vertically arranged, aninner shell inclosed within the outer and having its lower marginsecured thereto, the inner shell having a lower cylindrical portionforming a fire-box, and an upper semicylindrical portion above the frontof the fire-box forming a combustion-chamber, the top of said upperportion, and the top of said lower portion behind the combustion-chamberbeing in the form of half-domes, the bends in said inner shell beingarcs of large circles, a single brace between each of said half-domesand the outer shell, and a horizontally-arranged cylindrical shellrearwardly extending from the vertical shell and containing thefire-tubes, substantially as described and shown.

In testimony whereof I affix my signature in presence of two witnesses.

DAVID FITZGIBBONS.

Witnesses I MORTON J. SANFORD, J. F. MARSDEN.

